The Story of Invasive Species: Log Lunch with Mystic Professors Sofia Zepeda and Tim Pusack

At the penultimate Log Lunch of the semester attendees were joined by Williams Mystic professors Sofia Zepeda and Tim Pusack, who gave a collaborative talk discussing the story of invasive lionfish species. Zepeda, a professor of American Maritime History at Mystic, kicked off the talk with a brief introduction to the popular media portrayal of the lionfish as an extremely threatening species. Pusack, a professor of Marine Ecology at Mystic, followed up with a detailed description of the lionfish and how it functions as an invasive species. For starters, he pointed out that an invasive species differs from a non-native species in ecological terms because an invasive species has a documented negative impact on the invaded regions they populate. A non-native species on the other hand has a net-neutral effect. Lionfish fit into the invasive species category due to their negative impact on smaller coral reef fish populations, species that are essential to the wellbeing of those ecosystems. In the last thirty years, the Indo-Pacific-native lionfish has rapidly spread throughout the south Atlantic, the Gulf of Mexico, and the Caribbean. The fish have hearty, durable bodies and are very efficient predators, able to strike their prey rapidly using a vacuum-like feeding mechanism: the lionfish can draw water into its gills so quickly that fish in surrounding water get sucked into the mouth of the lionfish. 

The highly effective, deadly predation of the lionfish combined with their ability to disperse wide and far into new marine regions has led to their reputation as a highly threatening invasive species.  Zepeda spoke to how this understanding of the lionfish as a kind of public enemy in the world of marine ecology is representative of how we respond culturally to invasive species. In her own research, Zepeda has analyzed media coverage of the lionfish over the last twenty years. Overwhelmingly, the rhetoric surrounding the lionfish positions their rapid population growth as an act of war. Two of the headlines she mentioned exemplify this sentiment. The first from 2009 reads, “New Pirate of the Caribbean invades from Pacific,” and a second in 2014 says, “War on invasive lionfish in Atlantic waters yields first good news.” After sharing these examples, Zepeda asked her audience what kind of understanding they might have of the lionfish given this journalistic language. One student responded that this portrayal of the species positions lionfish as having a great deal of agency in a conflict that is represented as very black and white, good versus evil. 

The reality is that lionfish themselves are causing devastation to smaller fish populations in coral reefs in large part because of human action; due to the “hypnotic” beauty of the lionfish, many Americans sought them as pets. After discovering the voracious hunger and rapid growth of the fish, owners would release their pets into the wild, leading to an explosion of lionfish populations in nearby oceans. The big takeaway here is that these ecological issues are far more complex than their representations in mainstream media. Zepeda and Pusack together invited their audience to think about how the language we use to talk about science reveals how we are interacting with nature as well as with the change we experience in our environments. The story of the lionfish questions how our culture approaches problems and even suggests that we can do more to move beyond framing solutions within the context of a war against an invader. 

On the menu at Log Lunch this week was vegetable spring rolls, miso roasted turnips and bok choy, coconutty rice, and brown butter toffee chocolate chip cookies. All veggie produce came from Mighty Foods Farm.

Log Lunch is a CES program hosted every Friday at noon. During Log Lunch, a vegetarian meal prepared by Williams students is served, followed by a talk on an environmental topic. Speakers are drawn from both the student body and faculty of Williams, as well as from local, national, and international organizations. Learn more here.

BY CAMPBELL LEONARD ’25